TECHNICAL FIELD
[0001] The present invention relates to an apparatus and method for friction welding. Specifically,
the present invention relates to an apparatus and method for friction welding that
produces an arcuate oscillating motion.
BACKGROUND OF THE INVENTION
[0002] In general terms, a gas turbine engine has a compressor section, a combustion section
and a turbine section. Air travels axially through the engine within an annular flow
path. First, the air enters the compressor section. The compressor section pressurizes
the air. The air then travels to the combustion section. The combustion section introduces
fuel to the air and ignites the mixture. The air then travels to the turbine section.
The turbine section extracts energy from the exhaust to drive the compressor. The
air then exits the engine as thrust.
[0003] The compressor and turbine sections each include one or more bladed rotor assemblies.
A rotor assembly includes a disk/rotor and a plurality of blades secured the outer
diameter of the disk. Several techniques exist to secure the blades to the disk.
[0004] One such technique uses complementary shaped retention features on the disk and the
blades. Specifically, the disk includes an arrangement of slots, each receiving a
dovetail or fir tree arrangement on the root of the blade. This technique can have
issues with manufacturing (
e.
g. the machining of complex slots in the disk) and weight.
[0005] Another technique involves the bonding or welding of the blades to the disk. Bonding
the blades to the disk produces an integrally bladed rotor (IBR) assembly. This technique
is preferred when considering possible weight savings. A rotor assembly using the
aforementioned slot/dovetail arrangement will weigh more than an IBR since the IBR
does not require blade platforms or roots.
[0006] One method of producing an IBR is friction welding. Friction welding utilizes complementary
interfacing surfaces of the blade and the disk. The friction welding machine rubs
the interfacing surfaces of the blade and the disk together in an oscillating pattern.
The friction created at the interface generates heat The heat produces a molten, preferably
plastic, state to the material at the interfacing surfaces.
[0007] As the parts rub, the machine applies a compressive force to increase pressure at
the interface. This forge load causes some of the molten material to exit the interface.
This flash flow of molten material from the interface by the forge load causes a gradual
decrease in part thickness (in the forge direction,
i.
e. perpendicular to the interface).
[0008] At a desired thickness, the machine terminates the rubbing of the blade and disk.
As a result, flash flow will cease. In addition, the interfacing surfaces of the blade
and the disk will cool. Upon cooling, the interface reverts to a solid structure.
The parts together are now joined together as one piece.
[0009] Conventional friction welding machines utilize a linear oscillating motion when rubbing
the blade and the disk together. Most conventional linear friction welding machines
hold the blade with the airfoil chord aligned with the axis of oscillation. The phrase
"airfoil chord" refers the straight line between the ends of the mean camber line
of an airfoil. The phrase "mean camber line" refers the locus of points equidistant
from the upper and lower surfaces of an airfoil.
[0010] This alignment has proven successful for blades with low camber. The term "camber"
refers to the distance between the airfoil chord and the mean camber line.
[0011] A common problem encountered by conventional linear friction welding machines is
notch effect. As the blade moves in relation to the disk, an overhang occurs at either
end of the oscillation path. The overhang has more direct exposure to the atmosphere
than the remainder of the interface between the parts. As a result, the overhang is
cooler than the remainder of the interface. In fact, the bond interface at the overhang
prematurely cools, causing notches.
[0012] The solution to the aforementioned notch effect is to provide extra material or sacrificial
tips to the blade.
[0013] As the camber of the airfoil deepens, however, overhang also occurs along the sides
of the blade where the edges of the two parts are not parallel to the linear axis
of oscillation. An airfoil with "deep" camber has leading and trailing edges extending
at an angle to the camber line greater than a low, or shallow, camber airfoil.
[0014] The use of the aforementioned sacrificial material along the sides of the blade is
not practical with deep camber airfoils. The present invention, however, provides
an effective solution.
[0015] EP-A-290 134 discloses a mechanism for producing an oscillating movement in a friction welding
apparatus.
DISCLOSURE OF THE INVENTION
[0016] It is an object of the present invention in a preferred embodiment at least to provide
an improved friction welding method and apparatus.
[0017] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus compatible with curved workpieces.
[0018] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus compatible with blades having camber.
[0019] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus compatible with blades having deep
camber.
[0020] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus that oscillates in a path that
better conforms to the mean camber line of the airfoil section of the blade.
[0021] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus that provides uniform flash flow.
[0022] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus that reduces notch effect.
[0023] It is a further object of the present invention in a preferred embodiment at least
to provide a friction welding method and apparatus that exhibits reduced machine loading.
[0024] From one aspect the present invention provides an apparatus for friction welding
a workpiece to a substrate as claimed in claim 1.
[0025] From another aspect the invention provides a method of friction welding a curved
workpiece as claimed in claim 9.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Other uses and advantages of the present invention will become apparent to those
skilled in the art upon reference to the specification and the drawings, in which:
Figure 1 is a schematic of a linear friction welding machine;
Figure 2 is an elevational view of one component of the linear friction welding machine
of Figure 1;
Figure 3 demonstrates the linear oscillating path of the workpiece produced by the
linear friction welding machine of Figure 1;
Figure 4 demonstrates the area on the substrate contacted by the workpiece during
the oscillation of the linear friction welding machine of Figure 1;
Figure 5 is a perspective view of a section of a rotor assembly having a blade with
an airfoil section exhibiting camber;
Figure 6 is an elevational view of a component of one embodiment of a friction welding
machine of the present invention;
Figure 7 demonstrates the arcuate oscillating path of the workpiece produced by the
friction welding machine of the present invention; and
Figure 8 demonstrates the area on the substrate contacted by the workpiece during
the oscillation of the friction welding machine of the present invention.
PREFERRED EMBODIMENTS OF THE INVENTION
[0027] Figure 1 provides a schematic of a linear friction welding (LFW) machine 100. The
LFW machine 100 bonds a workpiece W to a substrate S. A typical manufacturer of such
LFW machine 100 includes MTS Systems Corporation of Eden Prairie, Minnesota. Although
capable of accommodating any workpiece W and substrate S, Figure 5 displays the preferred
application of the LFW machine 100. The LFW machine 100 preferably bonds a blade 51
to a disk/rotor 53 to produce a rotor assembly 55 for a gas turbine engine (not shown).
[0028] The LFW machine 100 includes a frame 101 that supports a first section 103 and a
second section 105. The frame 101 could have any suitable arrangement and could be
made from any suitable material.
[0029] The first section 103 of the machine 100 corresponds to the substrate S. The first
section 103 includes a holder 107 for the substrate S, a platform 111 supporting the
holder 107, and an actuator 113 to drive the platform 111. The holder 107 and platform
111 could have any suitable arrangement and could be made from any suitable material.
[0030] The actuator 113 preferably drives the platform 111 towards the workpiece W along
a forging axis X. The actuator 113 should have the capability of providing sufficient
force to the substrate S for compression against the workpiece W. The actuator, preferably
hydraulically operated, receives commands from a processor 115. The processor 115
receives signals from sensors 119, 121. The first sensor 119 provides the processor
115 with data regarding compressive force. The second sensor 121 provides the processor
115 with data regarding the position of the substrate S along the forging axis X.
[0031] The second section 105 of the machine 100 corresponds to the workpiece W. Similar
to the first section 103, the second section 105 includes a holder 123 for the workpiece
W, a platform 127 supporting the holder 123, and an actuator 129 to drive the platform
127. The holder 123 and platform 127 could have any suitable arrangement and could
be made from any suitable material.
[0032] The actuator 129 preferably drives the platform 127 transverse to the substrate S
along a linear oscillation path Z. The actuator 129 should have the capability of
providing sufficient force to rub the workpiece W against the substrate S when under
compression by the actuator 113 of the first section 103. The actuator, also preferably
hydraulically operated, receives commands from the processor 115. The processor 115
receives a signal from a sensor 131. The sensor 131 provides the processor 115 with
data regarding the position of the workpiece W along the oscillation path Z.
[0033] Differently than the first section 103, the second section 105 includes a slide mechanism
135 secured to the frame 101 using known techniques. The slide mechanism 135 guides
the platform 127 along a linear oscillating path relative to the frame 101 when driven
by the actuator 129.
[0034] Figure 2 provides an elevational view of the slide mechanism 135. The figure also
shows, in phantom line, the location of the platform 127 and the actuator 129 relative
to the slide mechanism 135.
[0035] The slide mechanism 135 includes a base 137 secured to the frame 101. The base 137
includes at least one channel 139 therein. The channel 139 receives a complementary
shaped portion (not shown) of the platform 127. The complementary shaped portion of
the platform 127 is smaller than the channel 139 along the oscillation path Z to allow
movement of the platform 127 by the actuator 129.
[0036] To assist movement of the platform 127, the bottom of the channel 139 includes a
plurality of bearings 143. The bearings 143 are typically cylindrical roller bearings
that allow movement of the platform along the oscillation path Z.
[0037] Figures 3 and 4 highlight the drawback of using the aforementioned LFW machine 100
with a curved workpiece, such as the blade 51. As discussed above, the LFW machine
100 typically oscillates the blade 51 along the airfoil chord at an interfacing surface
57 of the blade 51. In other words, the oscillation path Z typically parallels the
airfoil chord at the interfacing surface 57 of the blade 51.
[0038] Figure 3 shows the possible range of movement of the blade 51. The blade 51 can travel
on a linear path in the oscillation path Z between one extreme 51' and another extreme
51". As seen in Figure 4, driving the curved blade 51 along the airfoil chord creates
a significant contact area 145 on the disk 53. Due to the size of the contact area
145, the blade 51 tends to lose material from the leading and trailing edges. The
conventional solution adds extra material to the leading and trailing edges of such
blades 51 to accommodate increased flash flow and notch effects. This solution, however,
is not practical with deep camber airfoils.
[0039] The present invention uses a different technique. Generally speaking, the present
invention alters the oscillation path of the machine from a linear movement oriented
relative to the airfoil chord of the blade 51 to an arc. Preferably, the arc is a
regular arc. In addition, the arc should more closely resemble the mean camber line
of the airfoil of the blade than the linear oscillation of conventional techniques.
[0040] Figure 6 demonstrates how the present invention can be implemented in the aforementioned
LFW machine 100. The present invention substitutes the aforementioned slide mechanism
135 with an improved slide mechanism 235. The slide mechanism 235 guides the platform
127 when driven by the actuator 129.
[0041] The slide mechanism 235 includes a base 237 secured to the frame 101. The base 237
includes at least one channel 239 therein. Differently than channel 139, channel 239
has the shape of a regular arc. In other words, the curved sides of the channel 239
share a common arc center (not shown). Accordingly, the width of the channel 239 remains
constant along a radial line to the arc center.
[0042] The shape of the channel 239 defines an arcuate oscillation path Z'. In other words,
the movement of the blade 51 across the disk 53 is a rotation about an axis transverse
to the surface of the disk 53 and passing through the common arc center. Preferably,
the arcuate oscillation path Z' conforms to the mean camber line of the airfoil section
of the blade 51 better than the conventional linear oscillation path.
[0043] The channel 239 receives a complementary shaped portion (not shown) of the platform
127 of the second section 105 of the machine 100. The complementary shaped portion
of the platform 127 is preferably arcuate, and has a constant width along a radial
line to the arc center across the entire length. The complementary shaped portion
of the platform 127 is smaller than the channel 239 along the oscillation path Z'
to allow movement of the platform 127 by the actuator 129.
[0044] To assist movement of the platform 127, the bottom of the channel 239 includes a
plurality of first bearings 243 similar to the bearings 143 in the slide mechanism
135. The first bearings 243 could be cylindrical roller bearings arranged along the
arcuate path of the channel 239. However, the present invention could use other suitable
bearing types.
[0045] The channel also includes a plurality of second bearings 247 along the side walls.
The second bearings 247 could also be cylindrical roller bearings extending transversely
relative to the first bearings 243. However, the present invention could utilize any
suitable bearing type.
[0046] The first and second bearings 243, 247 allow movement of the platform 127 along the
arcuate oscillation path Z'. Although shown in the figures as discrete sets of bearings,
the present invention could utilize any arrangement that allows arcuate movement of
the platform 127 when driven by the actuator 129. For example, the curved side walls
could have a hydrostatic-type bearing surface (not shown) for shallow camber blades.
[0047] Since the platform 127 moves along the arcuate oscillating path Z' while driven by
the stationary actuator 129, the present invention preferably uses a conventional
pivotable coupling 251. The coupling 251 transmits the motive force from the actuator
to the platform while allowing the platform to rotate relative to the actuator 129.
[0048] Figures 7 and 8 highlight the benefit of using the slide mechanism 235 in the LFW
machine 100. As discussed above, the LFW machine 100 typically oscillates the blade
51 generally along the mean chord line of the airfoil of the blade 51. In other words,
the oscillation path Z' follows the shape of the airfoil of the blade 51.
[0049] Figure 7 shows the possible range of movement of the blade 51. The blade 51 can travel
on the arcuate oscillation path Z' between one extreme 51' and another extreme 51".
As seen in Figure 8, driving the curved blade 51 along the mean chord line creates
a contact area 245 on the disk 53. The size of this contact area 245 is smaller than
the contact area 145 produced by linear oscillation of the blade 51. The specific
reduction in contact area will vary with the actual shape of the product. Preferably,
the slide mechanism 235 is designed with an arc that can accommodate several part
numbers (rather than using a discrete slide mechanism 235 for each part).
[0050] The reduced contact area 245 produces less material sweep off from the leading and
trailing edges of the blade 51 than conventional linear oscillation of the blade 51.
This results in a reduction in the amount of extra material required at the leading
and trailing edges of the blade 51 due to a reduction in flash flow and notch effect.
[0051] The reduced contact area 245 also lowers the frictional load on the actuator 129
in the oscillating path. In addition, the reduced contact area 245 also lowers the
forge pressure required from the actuator 121 for the same forge load in the linear
oscillating motion.
[0052] Finally, the reduced contact area 245 leaves less residual material that must be
removed to produce the finished part. In addition, the flash flow produced with the
present invention is more uniform around the interface between the blade 51 and the
disk 53.
[0053] The present invention also reduces overhung areas. Reduction occurs because the width
of the overhung area in the present invention equals the narrow dimension of the blade.
[0054] By oscillating the blade in this arrangement, the machine also becomes easier to
control. The machine exhibits lower forge displacement variation (
i.
e. noise) due to a reduced variation (sinusoidal) of actual forge load at the interface.
Lower noise levels obviate the need for band pass filters that can introduce delays
to the observable signal.
[0055] In addition to the aforementioned slide mechanism 235, other techniques to impart
an arcuate oscillating motion to the blade 51 are possible. For example, a mechanism
(not shown) to rotate the holder 123 during linear oscillation is possible. Also,
a mechanism (not shown) to impart linear motion to the platform 123 in a second direction
(transverse to the first direction) is possible.
[0056] The present invention has been described in connection with the preferred embodiments
of the various figures. It is to be understood that other similar embodiments may
be used or modifications and additions may be made to the described embodiment for
performing the same function of the present invention without deviating therefrom.
Therefore, the present invention should not be limited to any single embodiment, but
rather construed in breadth and scope in accordance with the recitation of the appended
claims.
1. An apparatus (100) for friction welding a workpiece (W) to a substrate (S), comprising:
a platform (127) for supporting the workpiece (W); and characterised by further comprising:
an actuator (129) producing a linear oscillating motion;
a slide mechanism (235) between said actuator (129) and said platform (127), said
slide mechanism converting said linear oscillating motion of said actuator (119) into
an arcuate oscillating motion of said platform (127);
whereby the platform (127) can move the workpiece (W) in said arcuate oscillating
motion against the substrate (S).
2. The apparatus (100) as recited in claim 1, wherein said actuator (129) is a linear
actuator.
3. The apparatus (100) as recited in claim 1 or 2, wherein said arcuate oscillating motion
follows a regular arc (Z').
4. The apparatus (100) as recited in any preceding claim, wherein said slide mechanism
(235) comprises:
a base (237); and
a guide (239) engaging said platform (127) and converting linear oscillating motion
of said actuator (129) into said arcuate oscillating motion of said platform (127).
5. The apparatus (100) as recited in claim 4, wherein said guide (239) comprises an arcuate
channel (239) in said base (237).
6. The apparatus (100) as recited in claim 5, wherein said guide (239) further comprises
a plurality of bearings (243, 247) in said channel (239).
7. The apparatus (100) as recited in claim 5 or 6, in combination with a said workpiece
supported on said platform, wherein the workpiece (W) is an airfoil (51) having a
mean camber line, and said arcuate channel (239) generally follows the mean camber
line.
8. The apparatus (100) as recited in any preceding claim in combination with a said workpiece
supported on said platform, wherein the workpiece (W) is an airfoil (51) having a
mean camber line and said arcuate oscillating motion generally follows said mean camber
line.
9. A method of friction welding a curved workpiece (W), having a leading edge and a trailing
edge, to a substrate, comprising the steps of providing an arcuate (129) oscillating
motion of said workpiece (W); and contacting said substrate (S) with said workpiece
(W) with a force sufficient to bond said workpiece to said substrate,
characterised by comprising the steps of:
providing an actuator (129) which generate a linear oscillating motion;
converting said linear oscillating motion of said actuator into said arcuate (129)
oscillating motion of said workpiece (W).
10. The method as recited in claim 9, wherein said actuator (129) is a linear actuator.
11. The method as recited in claim 9 or 10, wherein said arcuate oscillating motion follows
a regular arc (Z').
12. The method as recited in any of claims 9 to 11, wherein the workpiece (W) is an airfoil
(51) having a mean camber line, and said arcuate oscillating motion generally follows
said mean camber line.
13. The method as recited in any of claims 9 to 12, wherein said converting steps comprises
the step of providing a slide mechanism (235) between said actuator (129) and said
workpiece (W), said slide mechanism (235) converting said linear oscillating motion
of said actuator (129) into an arcuate oscillating motion of said workpiece (W).
14. The method as recited in claim 13, wherein said slide mechanism (235) comprises:
a base (237); and
a guide (239) engaging said workpiece (W) and converting said linear oscillating motion
of said actuator (129) into said arcuate oscillating motion of said workpiece (W).
15. The method as recited in claim 14, wherein said guide (239) comprises an arcuate channel
(239) in said base (237).
1. Vorrichtung (100) zum Reibungsverschweißen eines Werkstücks (W) mit einem Substrat
(S), aufweisend:
eine Plattform (127) zum Abstützen des Werkstücks (W);
dadurch gekennzeichnet, dass sie ferner Folgendes aufweist:
einen Aktuator (129), der eine lineare Pendelbewegung erzeugt;
einen Gleitmechanismus (235) zwischen dem Aktuator (129) und der Plattform (127),
wobei der Gleitmechanismus die lineare Pendelbewegung des Aktuators (119) in eine
bogenförmige Pendelbewegung der Plattform (127) umwandelt;
so dass die Plattform (127) das Werkstück (W) in der bogenförmigen Pendelbewegung
gegen das Substrat (S) bewegen kann.
2. Vorrichtung (100) nach Anspruch 1,
wobei der Aktuator (129) ein Linearaktuator ist.
3. Vorrichtung (100) nach Anspruch 1 oder 2,
wobei die bogenförmige Pendelbewegung einem regelmäßigen Bogen (Z') folgt.
4. Vorrichtung (100) nach einem der vorausgehenden Ansprüche,
wobei der Gleitmechanismus (235) Folgendes aufweist:
eine Basis (237); und
eine Führung (239), die mit der Plattform (127) zusammenwirkt und die lineare Pendelbewegung
des Aktuators (129) in die bogenförmige Pendelbewegung der Plattform (127) umwandelt.
5. Vorrichtung (100) nach Anspruch 4.
wobei die Führung (239) einen bogenförmigen Kanal (239) in der Basis (237) aufweist.
6. Vorrichtung (100) nach Anspruch 5,
wobei die Führung (239) ferner eine Mehrzahl von Lagern (243, 247) in dem Kanal (239)
aufweist.
7. Vorrichtung (100) nach Anspruch 5 oder 6 in Kombination mit einem auf der Plattform
abgestützten Werkstück,
wobei es sich bei dem Werkstück (W) um ein Strömungsprofil (51) mit einer Profilmittellinie
handelt und der bogenförmige Kanal (239) im Allgemeinen der Profilmittellinie folgt.
8. Vorrichtung (100) nach einem der vorausgehenden Ansprüche in Kombination mit einem
auf der Plattform abgestützten Werkstück (W),
wobei es sich bei dem Werkstück (W) um ein Strömungsprofil (51) mit einer Profilmittellinie
handelt und wobei die bogenförmige Pendelbewegung im Allgemeinen der Profilmittellinie
folgt.
9. Verfahren zum Reibungsverschweißen eines gekrümmten Werkstücks (W), das eine Vorderkante
und eine Hinterkante aufweist, mit einem Substrat, wobei das Verfahren folgende Schritte
aufweist:
Schaffen einer bogenförmigen (129) Pendelbewegung des Werkstücks (W); und
Kontaktieren des Substrats (S) mit dem Werkstück (W) mit einer Kraft, die ausreichend
ist, um das Werkstück mit dem Substrat zu verbinden;
dadurch gekennzeichnet, dass es folgende Schritte aufweist:
Bereitstellen eines Aktuators (129), der eine lineare Pendelbewegung erzeugt;
Umwandeln der linearen Pendelbewegung des Aktuators in die bogenförmige (129) Pendelbewegung
des Werkstücks (W).
10. Verfahren nach Anspruch 9,
wobei der Aktuator (129) ein Linearaktuator ist.
11. Verfahren nach Anspruch 9 oder 10,
wobei die bogenförmige Pendelbewegung einem regelmäßigen Bogen (Z') folgt.
12. Verfahren nach einem der Ansprüche 9 bis 11,
wobei das Werkstück (W) ein Strömungsprofil (51) mit einer Profilmittellinie ist und
wobei die bogenförmige Pendelbewegung im Allgemeinen der Profilmittellinie folgt.
13. Verfahren nach einem der Ansprüche 9 bis 12,
wobei der Umwandlungsschritt den Schritt der Bereitstellung eines Gleitmechanismus
(235) zwischen dem Aktuator (129) und dem Werkstück (W) aufweist, wobei der Gleitmechanismus
(235) die lineare Pendelbewegung des Aktuators (129) in eine bogenförmige Pendelbewegung
des Werkstücks (W) umwandelt.
14. Verfahren nach Anspruch 13,
wobei der Gleitmechanismus (235) Folgendes aufweist:
eine Basis (237); und
eine Führung (239), die mit dem Werkstück (W) zusammenwirkt und die lineare Pendelbewegung
des Aktuators (129) in die bogenförmige Pendelbewegung des Werkstücks (W) umwandelt.
15. Verfahren nach Anspruch 14,
wobei die Führung (239) einen bogenförmigen Kanal (239) in der Basis (237) aufweist.
1. Appareil (100) destiné à souder par friction une pièce (W) de travail sur un substrat
(S), comportant :
une plate-forme (127) destinée à supporter la pièce (W) de travail ; et caractérisé en ce qu'il comporte en outre :
un actionneur (129) produisant un mouvement d'oscillation linéaire ;
un mécanisme (235) à coulisse entre ledit actionneur (129) et ladite plate-forme (127),
ledit mécanisme à coulisse convertissant ledit mouvement d'oscillation linéaire dudit
actionneur (129) en un mouvement d'oscillation en arc de ladite plate-forme (127),
la plate-forme (127) étant ainsi en mesure de déplacer la pièce (W) de travail suivant
ledit mouvement d'oscillation en arc contre le substrat (S).
2. Appareil (100) selon la revendication 1, ledit actionneur (129) étant un actionneur
linéaire.
3. Appareil (100) selon la revendication 1 ou 2, ledit mouvement d'oscillation en arc
suivant un arc régulier (Z').
4. Appareil (100) selon l'une quelconque des revendications précédentes, ledit mécanisme
(235) à coulisse comportant :
une embase (237) ; et
un guide (239) interagissant avec ladite plate-forme (127) et convertissant ledit
mouvement d'oscillation linéaire dudit actionneur (129) en ledit mouvement d'oscillation
en arc de ladite plate-forme (127).
5. Appareil (100) selon la revendication 4, ledit guide (239) comportant un canal (239)
en arc dans ladite embase (237).
6. Appareil (100) selon la revendication 5, ledit guide (239) comportant en outre une
pluralité de roulements (243, 247) dans ledit canal (239).
7. Appareil (100) selon la revendication 5 ou 6, en combinaison avec une pièce de, travail
susmentionnée supportée sur ladite plate-forme, la pièce (W) de travail étant un profil
aérodynamique (51) présentant une ligne de cambrure moyenne, et ledit canal (239)
en arc suivant généralement la ligne de cambrure moyenne.
8. Appareil (100) selon l'une quelconque des revendications précédentes, en combinaison
avec une pièce de travail susmentionnée supportée sur ladite plate-forme, la pièce
(W) de travail étant un profil aérodynamique (51) présentant une ligne de cambrure
moyenne, et ledit mouvement d'oscillation en arc suivant généralement ladite ligne
de cambrure moyenne.
9. Procédé de soudage par friction d'une pièce (W) de travail incurvée, présentant un
bord d'attaque et un bord de fuite, à un substrat, comportant les étapes consistant
à imprimer un mouvement d'oscillation en arc (129) à ladite pièce (W) de travail ;
et à mettre en contact ledit substrat (S) avec ladite pièce (W) de travail avec une
force suffisante pour faire adhérer ladite pièce de travail audit substrat,
caractérisé en ce qu'il comporte les étapes consistant à :
mettre en place un actionneur (129) générant un mouvement d'oscillation linéaire ;
convertir ledit mouvement d'oscillation linéaire dudit actionneur en ledit mouvement
d'oscillation en arc (129) de ladite pièce (W) de travail.
10. Procédé selon la revendication 9, ledit actionneur (129) étant un actionneur linéaire.
11. Procédé selon la revendication 9 ou 10, ledit mouvement d'oscillation en arc suivant
un arc régulier (Z').
12. Procédé selon l'une quelconque des revendications 9 à 11, la pièce (W) de travail
étant un profil aérodynamique (51) présentant une ligne de cambrure moyenne, et ledit
mouvement d'oscillation en arc suivant généralement ladite ligne de cambrure moyenne.
13. Procédé selon l'une quelconque des revendications 9 à 12, ladite étape de conversion
comportant l'étape consistant à mettre en place un mécanisme (235) à coulisse entre
ledit actionneur (129) et ladite pièce (W) de travail, ledit mécanisme (235) à coulisse
convertissant ledit mouvement d'oscillation linéaire dudit actionneur (129) en un
mouvement d'oscillation en arc de ladite pièce (W) de travail.
14. Procédé selon la revendication 13, ledit mécanisme (235) à coulisse comportant :
une embase (237) ; et
un guide (239) interagissant avec ladite pièce (W) de travail et convertissant ledit
mouvement d'oscillation linéaire dudit actionneur (129) en ledit mouvement d'oscillation
en arc de ladite pièce (W) de travail.
15. Procédé selon la revendication 14, ledit guide (239) comportant un canal (239) en
arc dans ladite embase (237).